Modern semiconductor devices often include thousands or millions of components implemented as layers of conducting or semiconducting material deposited on a substrate. Costs to bring such devices to market may run into several million dollars for design and fabrication of photomasks used to construct the devices. As a result, semiconductor manufacturers seek to ensure that a device design is well-functioning prior to committing to costly mask fabrication. In some cases, it may be desirable to implement and test a modification to a previously manufactured semiconductor device to determine if a design correction or modification operates as intended.
Conventionally, modifications to previously manufactured semiconductor devices to implement design corrections have been made using focused ion beams (FIBs) for selective removal or deposition of material in one or more layers of a device. The FIB is repeatedly scanned across a region of the surface of a semiconductor device, to incrementally sputter away or deposit material at the surface. Device modifications using an FIB are made sequentially one at a time by either sputtering material to break one or more existing connections between components of the device or by depositing material to make a connection. Thus, a total time required to implement a series of device modifications may be prohibitively long as the number of desired modifications increases.
Furthermore, reliability of device modifications decreases as a number of total modifications increases. Each time the FIB is aligned in a new position to make an additional device modification in a series of modifications, the likelihood of a misalignment of the FIB in at least one position increases. This increases the chances that at least one of the modifications will cause unintended damage to a portion of the device. The likelihood of the FIB causing unintended damage also increases as the size of individual features decreases. As a result of the time and reliability constraints associated with FIBs, modifications to a device using an FIB are frequently not attempted if a total number of desired modifications exceeds about ten modifications.